Let (X 1,X 2,...,X n) and (Y 1,Y 2,...,Y n) be real random vectors with the same marginal distributions,if (X 1,X 2,...,X n)≤ c(Y 1,Y 2,...,Y n), it is showed in this paper that ∑ n i=1 X i≤ c...Let (X 1,X 2,...,X n) and (Y 1,Y 2,...,Y n) be real random vectors with the same marginal distributions,if (X 1,X 2,...,X n)≤ c(Y 1,Y 2,...,Y n), it is showed in this paper that ∑ n i=1 X i≤ cx ∑ n i=1 Y i and max 1≤k≤n ∑ k i=1 X i≤ icx max 1≤k≤n ∑ k i=1 Y i hold.Based on this fact,a more general comparison theorem is obtained.展开更多
It is proved that the right spread order is closed under the formation of parallel systems with independent and identical components. As an application,the simple upper bounds for both the mean and the variance of the...It is proved that the right spread order is closed under the formation of parallel systems with independent and identical components. As an application,the simple upper bounds for both the mean and the variance of the life length of a parallel system with independent and identical NBUE components are obtained. Furthermore,it is proved that the right spread order is also closed under increasing convex transformations under some conditions.展开更多
The purpose of this paper is to discuss the closure properties of increasing convex average order and NBUCA life distributions. Under the assumption that the units are only independent, characterizations of NBUCA clas...The purpose of this paper is to discuss the closure properties of increasing convex average order and NBUCA life distributions. Under the assumption that the units are only independent, characterizations of NBUCA class of life distributions are given. It is shown that NBUCA class is closed under the random maxima and the formation of parallel systems of independent units. As an application of the main results, the behavior of this class is developed in terms of the monotonicity of the residual life of k-out-of n systems given the time at which the （n -k ）-th failure has occurred.展开更多
基金the National Natural Science Foundation of China( 1 0 371 1 0 9)
文摘Let (X 1,X 2,...,X n) and (Y 1,Y 2,...,Y n) be real random vectors with the same marginal distributions,if (X 1,X 2,...,X n)≤ c(Y 1,Y 2,...,Y n), it is showed in this paper that ∑ n i=1 X i≤ cx ∑ n i=1 Y i and max 1≤k≤n ∑ k i=1 X i≤ icx max 1≤k≤n ∑ k i=1 Y i hold.Based on this fact,a more general comparison theorem is obtained.
文摘It is proved that the right spread order is closed under the formation of parallel systems with independent and identical components. As an application,the simple upper bounds for both the mean and the variance of the life length of a parallel system with independent and identical NBUE components are obtained. Furthermore,it is proved that the right spread order is also closed under increasing convex transformations under some conditions.
基金The Science Foundation of Shaanxi Pro-vincial Educational Department (06JK325)
文摘The purpose of this paper is to discuss the closure properties of increasing convex average order and NBUCA life distributions. Under the assumption that the units are only independent, characterizations of NBUCA class of life distributions are given. It is shown that NBUCA class is closed under the random maxima and the formation of parallel systems of independent units. As an application of the main results, the behavior of this class is developed in terms of the monotonicity of the residual life of k-out-of n systems given the time at which the （n -k ）-th failure has occurred.
